Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super shout from the rooftops car that I am ready to drive off a cliff. had a idle surge hardship that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After aggravating 2-3 alternative used IAC s, I took it to the master tech at lexus. He said it was the IAC valve. He tried my used ones.. and finally a rebuilt one. yet had issues. back up to the dealer.. this times he says, it needs a ECU. I did a lot of research on them, and found that its a common burden once this car.. bought a used one.. more trouble. had the indigenous one rebuilt by a specialist.. and that s where I am at now.. Put it in tonight and the car idles at 2k rpm. Does the TPS dependence to be re-adjusted? The master tech did every sorts of diagnostics on all aligned parts (tps, maf, iac). 0-200 every period I say yes it pull off the dealer for diagnostics.. upon going problems are truly adding up. I m hesitant to lie alongside the tps if he had it dialed. Any insight? Thanks in advance. Jason
Thanks for your response. I just checked what you mentioned, that I hadn't already checked, except fuel pressure.Let me say you a tiny more just about the suffering history. It currently has a master tech recognized idle expose control valve and tps installed. without disturbing anything, the last (used) ecu and my original, would rule in the car without this symptom.
past I begin the car, the engine surges taking place along with 1200 and 2000 rpm support and forth. I untouched the IAC and the TPS subsequently no tweak in symptoms. I have noticed that several Lexus SC's have this similar issue. Prior to this I would have to adapt the idle quickness screw to lower the rpm and it would keep for a while. Now, the engine is at all times surging to the lessening where I cannot steer it for alarm bell of broken to the drive train. Any experienced solution?